How solid water has an open crystal structure that resembles a?

Solid water, or ice, has an open crystal structure that resembles a hexagonal lattice. This arrangement occurs because of the hydrogen bonds between water molecules, which create a spacious network. The open structure results in lower density compared to liquid water, allowing ice to float. This unique property is crucial for aquatic ecosystems, as it insulates the water below and maintains a stable environment for aquatic life.